This invention relates to a material for wrapping a pallet or like object, particularly to a stretch film laminated with a relatively narrow auxiliary band. The invention further applies to a method of stretch film wrapping.
Various stretch films are available today for wrapping diverse packages and other goods. One important use of stretch films is to wrap pallets of stacked boxes or the like. In such processes, a pallet of containers is wrapped with several turns of a stretch film of substantial width and many various techniques for doing so are known. The stretch film used is capable of substantial elongation, and by maintaining the film under adequate tension as it is passed around a pallet, not only does the film conform to corners and other irregularities, but it also remains under tension to tightly retain the containers against one another and upon the pallet. Sharp corners and the like can, however, tear the film, and to avoid this one must be judicious in applying tension to the film particularly when negotiating such corners. Stretch films are generally transparent and non-descript. They are difficult or impossible to print upon; when printing can be done, the printing process may approximately double the cost of the film.
U.S. Pat. No. 4,499,706 to Scheller indicates an awareness of the problem of film tearing at corners and provides, to resist such tears, a tube of film that is tucked in at its edges to provide extra layers of film at the points most likely to encounter container corners.
To avoid tears, one can use film of greater thickness, but this necessarily increases costs and the amount of tension needed to produce a desirable degree of elongation.
We have found that one can obtain the advantages of a heavy gauge or laminated film by providing a film of standard thickness with an additional, much narrower, band of film to improve tear and puncture resistance. The relatively narrow band may be of the same type of material as the film and the same thickness, or it can be of different gauge or different material. Additionally, the narrow band may have visual characteristics such as color or printed indicia for identifying the goods, or the shipper, or for other purposes. The economic advantages of the invention are particularly significant when the band is imprinted, because one may imprint a single roll of material and sever it into many narrow bands each suitable for laminating with a standard unprinted film.